Case History A-3

O x y g e n R e l e a s e C o m p o u n d ADVANCED ™

High Benzene Concentrations Reduced Using ORC Advanced – Sheboygan, WI SITE SUMMARY Elevated levels of petroleum hydrocarbons were discovered near the former dispenser island at a former service station in Sheboygan, WI. In hopes of reducing concentrations, soil excavation activities took place in June 2003. A total of 500 tons of hydrocarbon-impacted soils were removed and transported to a landfill for disposal. However, residual contamination continued to affect the groundwater after the excavation. By March 2004, benzene and ethylbenzene had risen to 2,500 ug/L and 1,300 ug/L, respectively. In situ bioremediation using ORC Advanced was chosen to reduce BTEX, naphthalene, and trimethylbenzenes. In the northwest corner of the site, the location of the former UST basin, a total of 480 pounds of ORC Advanced was injected. In the southeast corner, the area of highest contamination, a total of 2,370 pounds of ORC Advanced was injected. REMEDIATION APPROACH

¾ Remediation Objective: Reduce concentrations of Benzene to Table 1. Cleanup Goals cleanup goals at the entire site. See Table 1. Contaminant Concentration ¾ Application Type: Grid Benzene 5 ug/L ¾ Product: ORC Advanced Toluene 1,000 ug/L ¾ Quantity Applied: 2,850 lbs Ethylbenzene 700 ug/L ¾ Application Rate: NW Corner–4 lbs/ft; SE Corner-11.9 lbs/ft Xylenes 10,000 ug/L ¾ Injection Spacing: 10 ft Figure 1. Site Map Monitoring Well ¾ Product Cost: $24,225

Injection Point SITE CHARACTERISTICS ______MW-5 General ¾ Name: Former Marathon Unit #3697 ¾ Location: Sheboygan, WI

¾ Industry: Service Station ¾ Contaminants of Concern:

Table 2. Well MW-8 Concentrations Contaminant Concentration MW-4 Benzene 1,700 ug/L Toluene 530 ug/L Ethylbenzene 1,300 ug/L

Xylenes 3,190 ug/L MW-2 GW Flow Hydrogeology 2 ¾ Treatment Area: NW Corner 1,200 ft 2 MW-1 SE Corner 1,800 ft ¾ Soil Type: Silty sand lenses in clay matrix

¾ Groundwater Flow Direction: Southeast MW-8 ¾ Depth to Groundwater: 12-15 ft N

All Rights Reserved 2006 Regenesis -1011 Calle Sombra, San Clemente, CA 92673 www.regenesis.com RESULTS Percent Contaminant Reduction Post Treatment Concentrations Contaminant Percent Reduction Contaminant Concentration Benzene 98% Benzene 30 ug/L Toluene 96% Toluene 18 ug/L Ethylbenzene 99% Ethylbenzene 5.8 ug/L Xylenes 96% Xylenes 115 ug/L

Concentrations vs. Time

Well MW-8 Concentrations Benzene Concentrations

3500 180 ORC-Advanced

3000 ORC-Advanced 160

L) L) Application

/ Application / 140 2500 B ug

(ug

(

120 MW-2

n T o

o 2000 n

i i 100 MW-4

t E t

a

a

r 1500 r 80 MW-5 X t

nt n 60 1000

ce ce n 40

o 500 on

C C 20 0 0 -150 -60 30 150 -150 -60 30 150 Date Date

Naphthalene Concentrations

Note: The significant decrease seen from day -60 is 180 ORC-Advanced indicative of the gap between data points as concentrations 160 Application most likely stayed their course, increasing, until ORC

L) / 140 g Advanced was injected and a new data point collected at

u

( 120 MW-1 day 30.

n o 100 MW-4

i

t

a r 80 MW-5

t n 60 ce 40

on

C 20 0 -150 -60 30 150 Date

CONCLUSION Groundwater sampling results after excavation activities show an increasing trend of contamination. On average, concentrations continued to increase up until the ORC Advanced application due to residual contamination. Concentrations peaked before ORC Advanced injection followed by a significant reduction across the plume. In well MW-5, benzene spiked to 160 ug/L while naphthalene rose to 170 ug/L and in well MW-4 BTEX, naphthalene and trimethylbenzenes all increased. Significant decreases of all contaminants were seen shortly after ORC Advanced injection. In well MW-8 total BTEX was reduced from 6,720 ug/L to 168.8 ug/L, a 97% reduction. Naphthalene concentrations were above the MCL of 20 ug/L in wells MW-1, MW-4, MW-5. ORC Advanced reduced concentrations to non-detect in wells MW-4 and MW-5, leaving 38 ug/L in well MW-1. Monitoring is on-going as concentrations continue to decrease towards MCLs.

CONTACTS Consultant: Steve Sittler Regenesis: Scott Mullin Handex of Indiana Central U.S. Regional Manager 630-753-0836 [email protected]

All Rights Reserved 2006 Regenesis -1011 Calle Sombra, San Clemente, CA 92673 www.regenesis.com